§ 19. 



RED CORAL. 619 



solidity, and the slightest shock detaches it from its base. 

 Becoming the sport of the waves, the polypes perish, their 

 brilliant skeleton is exposed, and cast upon the shore ; the 

 bright colour soon disappears, and the coral, reduced to 

 fragments by the attrition of the waves, becomes mixed with 

 the remains of shells and other marine exuviae : in this 

 state it is drifted inland by the winds, and assists in form- 

 ing those accumulations of the spoils of the sea, which 

 constitute many of the modern conglomerates described in 

 a previous lecture (ante, pp. 85, 90). 



19. Tubipora. — This group of corals is well known, from 

 the elegance and beauty of one species (Sarcinula musi 'calls, 

 or Organ-pipe coral), which is common in most collections. 

 This coral is composed of parallel tubes, united by lateral 

 plates, or transverse partitions, placed at regular distances ; 

 (PI. VI. figs. 7, 9) in this manner large masses, consisting 

 of a congeries of pipes or tubes, are formed. When the 

 animalcules are alive, each tube contains a polype of a 

 beautiful bright green colour, and the upper part of the 

 surface is covered with a gelatinous mass formed by the 

 confluence of the polypes ; a magnified view of a polype 

 and sections of two tubes, is here represented (PI. VI. 

 fig. 7). This species occurs in great abundance on the 

 coast of New South Wales, of the Eed Sea, and of the 

 -Molucca Islands, varying in colour from a bright red to a 

 deep orange. It grows in the shape of large hemispherical 

 masses, from one to two feet in circumference ; these first 

 appear as small specks adhering to a shell or rock ; as they 

 increase, the tubes resemble a group of diverging rays, and 

 at length other tubes are produced on the transverse plates, 

 thus filling up the intervals, and constituting a uniform 

 tubular mass ; the surface being covered with a green 

 fleshy substance, beset with stellular animalcules. The 

 protruded polype of another beautiful species of Tubipore 

 (Tubipora rubeola) is represented magnified, PL VI. fig. 4; 



